The joint agents, Knight Frank & Rutley and Savills, have put a pounds 4.5m price on the Suffolk property, which is Grade I listed and regarded as one of Britain's most important neo-classical mansions.
Receivers were appointed last year to sell the 187-hecatre (469- acre) estate landscaped by Capability Brown, after the death of Abdul Amir Al-Ghazzi, an Iraqi businessman who bought it from the Government in 1981. Michael Heseltine, then Secretary of State for the Environment, made the decision to sell Heveningham 11 years after it was bought by the state from the Vanneck family, for whom it was built in 1752.
Last December, when again in charge of the Department of the Environment, Mr Heseltine told the Commons that he would not exercise a right to buy that had been written into the 1981 deal.
His decision was a blow to the campaign groups who alleged that priceless architectural heritage had been damaged by alterations. The Suffolk Building Preservation Trust said that since the 1981 sale there had been 'a tragic catalogue of neglect, misfortunes and disasters'.
The joint agents said that contrary to many reports, Mr Al- Ghazzi's company had spent many millions of pounds renovating the historic house.
Heveningham will be opened to the public on afternoons from 7 July to 31 July, excluding Mondays, in what the agents described as 'possibly the last opportunity to see the property'.